MathDB
r=b+\frac{1}{a_1}+\frac{1}{a_2}+...+\frac{1}{a_n}

Source: Ukraine TST 2010 p12

May 5, 2020
algebrarationalSumreciprocal sumnumber theory

Problem Statement

Is there a positive integer nn for which the following holds: for an arbitrary rational rr there exists an integer bb and non-zero integers a1,a2,...,ana _1, a_2, ..., a_n such that r=b+1a1+1a2+...+1anr=b+\frac{1}{a_1}+\frac{1}{a_2}+...+\frac{1}{a_n} ?